Prototype for a Sitzmaschine

This prototype (ca. 1928) is identical to the B25, not only in its complete characteristics, but also in its exact dimensions. The essential difference between the two is that the prototype is a cantilevered design, while the B25's seat gets its elasticity and movement from springs that attached to the frame. All construction details point unequivocally towards Marcel Breuer. For instance, the screw connections and the hooks for the adjustable backrest are very similar to those he used for the tea trolley B54 After his revolutionary invention of the tubular steel chairs combined with the Eisengarn-Gurtbespannung, it was evident to Breuer that there would be a new demand for upholstered sitting-furniture. As a result, in all his Berlin interiors, Breuer outfitted the B35 with upholstery. Even though the diameter of the steel tube of the prototype is identical to that of the mass-produced chairs, the actual thickness of the steel tube, and consequently the weight of the actual prototype, is considerably greater. The relative higher weight of the chair clearly points towards a prototype, since the stability of the construction was only testable once the chair was built. It is highly probable that this specimen is a prototype of the B25 series: the cantilevered seat of this chair apparently seemed too long to Breuer, and subsequently he developed the B25 with its backwards spring-frame attachment. At the same time, he used the cantilevered prototype as the basis for the development of the B35 Both armchairs were evidently designed in 1928 The anterior crossbar of this chair is still welded together, which is an additional clear indication that it is a prototype model. The same crossbar is also welded in different versions of the B35 Chromium plating became a technical possibility only after 1928 The prototype is nickel-plated, which means it was built in early 1928 All of the B25 models known to exist today were made by Thonet in Vienna, where the prototype was discovered. The cover of the upholstery is a typical "modern" Viennese cloth design.
Manfred Ludewig

Chrome-plated tubular steel, bolted connections, ebonized wood armrests 357/16 in. (90 cm) high